This invention relates to package cartons, and more particularly to apron-type sortation conveyors provided with branch lines to which selected cartons can be diverted out of the main line. The present invention provides an addition to or an improvement on the sortation conveyor disclosed in the application of Thomas C. Yu et al, Ser. No. 675,156, (hereinafter referred to as "Case A"), filed Nov. 27, 1984 and assigned to the same assignee as this application, hereinafter referred to as "Case A".
The invention is particularly concerned with such conveyors wherein the branch lines are arranged in directly opposed pairs along the main conveyor line. The primary object of the invention is to provide such a conveyor wherein such pairs of branch lines can be spaced as closely as possible to each other along the main line.
The sortation conveyor disclosed in Case A includes a frame defining the main line of the conveyor and at least one branch outlet therefrom, an endless apron supported for movement on the frame to define the top conveying run and a bottom return run, a plurality of pusher elements mounted for movement with the apron and also for sliding movement across the apron from one side thereof to the other, and selectively operable means for causing a desired number of pusher elements to move across the apron as they move forward with it and thereby to push the selected carton from the apron onto the selected branch conveyor.
More specifically, each of the pusher elements is equipped with a guide pin which depends therefrom, and when the pusher elements are in their normal rest positions along one side of the conveyor apron, each of these pins will pass in succession through a channeled switch member pivoted to swing between a retracted position parallel with the course of the apron and an advanced position at an acute angle to the apron course wherein it cooperates with the guide pins on successive pusher elements to divert those elements away from the side of the apron.
As soon as each diverter pin leaves the switch member, it is caused to engage a guide track which extends across the frame at an angle to the apron course. The forward movement of the pusher element with the apron will also cause it to be cammed by the guide track laterally across the apron and thereby to cooperate with successive similarly cammed pusher elements to push the selected carton onto the branch conveyor. Provision is made for returning each diverted pusher elements back to a rest position during its travel on the bottom return run of the apron back to the upstream end of the main conveyor line.
The operation of the conveyor disclosed in Case A requires that the guide pin on each diverted pusher element be continuously guided across the width of the apron until it completes its carton-ejecting movement. This is readily accomplished in that application by guiding the guide pin by means of a guide track extending at an angle across the entire width of the conveyor. That arrangement, however, requires that if it is decided to have branch outlets on both sides of the main conveyor, they cannot be located opposite each other but must be spaced alternately on the two sides of the main conveyor. The primary objective of the present invention is to modify that conveyor in order to make it possible to accommodate branch conveyors arranged in directly opposed pairs along the main conveyor line.